The present invention relates to a contents delivery system, which is capable of delivering multimedia contents by electronic mails (E-mails).
Conventionally, multimedia contents including image data of pictures and photographs, music data, text data are sent from a data transmitter to a data receiver by several ways.
For example, in a first way, the data transmitter is connected to the corresponding data receiver by a telephone line or an ISDN (trademark) line, and the data receiver is directly connects to the data transmitter via the line so as to receive the contents.
In a second way, the data transmitter is connected to a plurality of the data receivers by a switchboard and telephone lines so as to deliver the contents to the data receivers.
In a third way, the data receivers are connected to a communication network, e.g., LAN, the internet, to which a server, which acts as the data transmitter, is connected, and the data receiver download the contents from the server.
A desired contents delivery system should deliver the contents efficiently, securely, easily and economically.
To efficiently deliver the contents, the contents should be simultaneously delivered to a plurality of the data receivers.
To securely deliver the contents, the data transmitter should check if the contents are received by the data receivers.
To easily deliver the contents, the data transmitter should assign detail action of the data receivers, which have received the contents. If the data transmitter is able to control the action of the data receiver, for example the contents, which have been compressed and delivered, can be automatically thawed and stored in an assigned place. Therefore, a user of the data receiver need not process the received contents, so that the contents can be gained easily.
To economically deliver the contents, no specific process and no specific means should be required. The contents should be delivered by existing infrastructures.
However, the conventional contents delivery systems cannot satisfy the requirements of the desired delivery system.